How to create a prefixed list of transform data for objects?
You can use startswith('prefix') to detect objects' names start with this prefix.

I have changed the keys so there values don't get overwritten by new ones ,this is the portion of the code that needs to be changed :

def RunPerFrame(scene):
    prefix = 'prefix' 
    url = ''
    values = { 'msgInstruction=' : 'MOVE_OBJ'}

    for obj in bpy.data.objects:
        print(obj.name)
        if obj.name.startswith(prefix):
            mat = bpy.context.object.matrix_world
            loc = mat.to_translation()
            rot = mat.to_3x3().to_quaternion()
            scale = obj.dimensions
            qtX = round(rot.x,3)
            qtY = round(rot.y,3)
            qtZ = round(rot.z,3)
            qtW = round(rot.w,3)
            loX = round(loc.x,3)
            loY = round(loc.y,3)
            loZ = round(loc.z,3)
            scX = round(scale.x,3)
            scY = round(scale.y,3)
            scZ = round(scale.z,3)

            name = obj.name.replace(prefix,'')
            this_object = {'object=': name,  name+'_rotQuat=' : str(qtX) + ',' + str(qtY) + ',' + str(qtZ) + ',' + str(qtW), name+'_objLoc=' : str(loX) + ',' + str(loY) + ',' + str(loZ), name+'_objScale=' : str(scX) + ',' + str(scY) + ',' + str(scZ) }
            values.update(this_object)